围绕氟化镁共形整流罩的热障效应展开分析，模拟了真实飞行状态，建立了整流罩气动加热及其内部传热过程的有限元分析模型，计算不同飞行速度下整流罩的气动热载荷及平均温度；再根据红外探测基本原理，分析各个温度下整流罩的热辐射及其对探测系统成像质量的影响，计算探测器达到饱和状态时整流罩的临界温度，即研究热障效应产生机制；最后用成像试验对分析结果加以验证。分析结果表明，对于该红外成像探测系统，氟化镁共形整流罩的临界温度约为460 K，即在Ma=3的末制导阶段及Ma=4的情形下，热障效应显著，若想进一步加快红外成像制导**的飞行速度，必须对热障效应加以抑制和校正。各项结论对认识热障效应机理及其校正方法有一定借鉴意义。

This paper focuses on the thermal barrier effect of magnesium-fluoride conformal dome. Firstly, the real flight process was simulated and a finite element analysis model of the fairing aerodynamic heating and internal heat transfer were established under different flight speeds, the aerodynamic-thermal loads and the average temperature of dome was calculated. Secondly, according to the basic principles of infrared detection, each temperature dome heat radiation and its effects on the imaging quality of the detection system were analyzed, the critical temperature of dome was calculated when detector reached the saturation condition to study the mechanism of the thermal barrier effect. Finally, imaging tests were carried out for validation of analytical results. The results show that the critical temperature of dome when detector reaches the saturation condition is about 460 K, the thermal barrier effect is remarkable under the condition of Ma=4 and final guidance in Ma=3. In order toaccelerate the infrared imaging guided weapons flight speed, the thermal barrier effect must be corrected. The conclusions has certain reference for understanding the mechanism of the thermal barrier effect and correction methods.